A Minotaur-like creature feeds on the faith (not fear) of its victims once they retreat into their beliefs.
In this episode, the Behavioral Analysis Unit (BAU) tracks an amateur surgeon who is performing non-consensual leg amputations. [S8E4] God Complex
The experiment goes horribly wrong, leading to a moral crisis about how many "innocent" lives should be sacrificed for the greater good. Doctor Who (Series 6, Episode 11) A Minotaur-like creature feeds on the faith (not